Closet flange will not fully insert into soil pipe - solutions?

[Temp945]

Hi all,

I'm about to set a new toilet on a new soil pipe that I recently installed.

I installed my soil pipe about a foot higher than the subfloor so that I could later trim it flush after the finished floor was installed. Last night I cut the soil pipe flush with the finished floor.

Now I'm ready to install the toilet flange. In preparation - since I'm not a pro, and I want to do it right - I did some reading and found a couple of instances where individuals were not able to get their closet flange to insert all the way into their soil pipe. I assumed that this was due to inadequate preparation with primer and cement leading to the interference fit providing too much resistance. But I also saw a video where the plumber stated that he cuts the soil pipe about 1/2" below the finished floor so that he can fully insert the closet flange, because otherwise the flange wants to sit a bit higher than the soil pipe.

This morning I did a test fit with an extra closet flange on a short section of 4" pipe to see if I could get the flange to insert all the way into the pipe. I carefully prepared the pipe and flange with primer and cement and was able to insert the fitting easily with just hand/arm force, but for good measure, I also stood on it to make sure it was as fully inserted as possible.

What I found was that the flange sits about 1/8" proud of the pipe. This would cause the flange to sit proud of the finished floor, with a gap between the floor and the stainless ring. In one of the attached photos, I am holding a piece of wood flush with the soil pipe to indicate the finished floor and you can see the gap.

Have any of you run into this issue before?

The simple solution would be for me to get an appropriate tool to cut about 1/4" to 1/2" of the soil pipe so that it sits shy of the finished floor. Are there any other solutions?

Perhaps the specific closet flange that I purchased has a design defect? It is designed for 3" hub or 4" inside - maybe the hub connection works fine but there is a problem when used with 4" inside connections? Here is the one I purchased:
https://www.supplyhouse.com/Sioux-C...ide-Open-Flange-w-Stainless-Steel-Swivel-Ring

Thanks for reading!

 

[Reach4]

Initially I had thought your first picture showed a long-tailed flange instead of Sioux Chief
887-PM.

Your last photo seems to show the pvc pipe a little higher than the tile itself, with mortar ramping up from the floor to the top of the pipe.

This flange rim is thin enough that I think an extra 1/8 inch will not interfere with the toilet. Think of how thick those all-PVC flanges are. I would add spacers of some sort before tightening the screws. A stack of stainless steel fender washers under each screw hole might be good, or maybe some shims on each side of each screw before tightening. I am not a pro.

 

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[Temp945]

Thanks, Reach.

The first three photos are all of my test fit using a Sioux Chief 887-PM into a short section of 4" PVC pipe.

The soil pipe currently is in fact about 1/16" - 3/32" proud of the surrounding tile (see the photo below). The floor isn't *completely* level either

You make a good point about how thin the flange is, especially compared to some of the all-pvc ones.

One of my concerns with the flange not sitting directly on the floor is getting a good seal with the wax ring. I don't want the wax ring squishing through the bolt holes and filling the void under the ring rather than squishing against the toilet horn.

I'm leaning towards getting an inside PVC pipe cutter and taking the soil pipe down below the finished floor about 1/4" - 1/2"...

Any other opinions?

 

[Reach4]

The first three photos are all of my test fit using a Sioux Chief 887-PM into a short section of 4" PVC pipe.

The purple primer made me think the flange was already glued.

You don't expect to dry fit PVC and get it apart. There is an interference fit, and the primer+glue melts enough plastic to allow seating, and also welding of the plastic.

A rasp could taper the top of that pipe, and maybe let you take the height down a bit.

 

[WorthFlorida]

I wouldn't worry about that gap. Most, if not all of the seal, is the two inches or more of PVC below the rim. With the proper amount of primer/cleaner and solvent all around, it will be a tight seal. All of the weight of the toilet is on the floor, not the flange. The wax ring makes up the gap between the flange and bowl. To make you feel better it wouldn't hurt to ream out a little PVC on the inside to give it a tapered edge, no more than an 1/8". From the picture is looks like there is a tapered edge.

 

[Temp945]

@Reach: Yes, for the test fit, I actually glued the extra flange to the scrap pipe to see if the flange would insert all the way so that the flange would lay flat on the finished floor.

@WorthFlorida: I'm not worried about the PVC seal - I'm sure that will be fine. I'm concerned about the flange sitting off of the finished floor and the effect that would have on the wax seal. For instance, the pressure of the toilet's horn could push wax out through the bolt holes into the void beneath and cause a poor wax seal.

Also, I do always taper the outside edge of my PVC pipes (with a Reed DEB4) and always use a PVC reamer on the inside (with a Milwaukee reaming pen). That did not seem to solve the issue with the test glue-up.

 

[Reach4]

@Reach: Yes, for the test fit, I actually glued the extra flange to the scrap pipe to see if the flange would insert all the way so that the flange would lay flat on the finished floor.

Cool. Above and beyond. If you wanted to really enhance your test, you could cut a cross section after removing the metal part.

For instance, the pressure of the toilet's horn could push wax out through the bolt holes into the void beneath and cause a poor wax seal.

I don't see that being a problem, but could movement happen on the PVC pipe causing the wax to decompress? You don't want to decompress wax. When using wax, dry fit the toilet first, and position shims, and only then drop the toilet onto the wax.

Also, I do always taper the outside edge of my PVC pipes (with a Reed DEB4) and always use a PVC reamer on the inside (with a Milwaukee reaming pen).

I was thinking of rasping away enough material to clear any interference. That mortar could maybe be chiseled down, rather than buying a concrete grinding wheel for your angle grinder.

 

[Jadnashua]

On some flanges, the transition from horizontal to vertical is not square...it's slightly rounded...so, when you try to set it on the pipe, that radius holds it off slightly from being fully seated.

Two things you could try:
- chamfer the inside of the waste pipe
- make it slightly shorter than flush with the attachment ring's bottom

I suppose if you had a lathe, you could make it square, but it's much easier to deal with the pipe.

 

[Temp945]

jadnashua: you might be right. The transition is not square but rather slightly rounded. It is a very subtle roundover (1/8 or 1/16) but it might be the culprit.

The test glue up that I did used a pipe with a chamfer ID (done with my Milwaukee reamer pen) but this still did not allow it to sit flush.

I think the easiest solution is to make the soil pipe just a bit shorter. I purchased an interior PVC pipe cutter today and plan to use it tonight.

 

[Reach4]

I think the easiest solution is to make the soil pipe just a bit shorter. I purchased an interior PVC pipe cutter today and plan to use it tonight.

Good luck with that.

What about your rim of mortar?

 

[Temp945]

Reach: what looks like mortar is actually white grout (Spectralock 1, which gets very hard).

Anyway, maybe I should forget about the pipe cutter and rasp away at the edge like you suggested. I suppose that might actually be easier than cutting and should have the same effect, with the advantage of leaving the edge of the soil pipe flush with the floor so as to support the surrounding grout.

 

[Jeff H Young]

looks like you just need to glue a ring on. I dont see a problem Are you thinking your flange is going to be too high? 1/8 inch? like reach 4 said a couple washers or even glue it in as is it looks rock solid then run your screws down till the just hit the flange, should be good the flange is getting pulled up by the bolts but the washers underneath slightly better job. no movement

 

[Temp945]

Thanks everyone for your help

I took the advice from Reach and jadnashua and chamfered the inside of the soil pipe. I just used my reamer pen (rather aggressively) and it worked great. After I did that, I did a dry test fit with the closet flange and it went in noticeably deeper. When I did the actual glue up, it went in all the way, no problem.

As an amateur, I'm sure I overthought this and probably just could have shimmed it. But the important thing is that the toilet is installed and flushing

Thanks again!

 

[Jeff H Young]

Thanks everyone for your help

I took the advice from Reach and jadnashua and chamfered the inside of the soil pipe. I just used my reamer pen (rather aggressively) and it worked great. After I did that, I did a dry test fit with the closet flange and it went in noticeably deeper. When I did the actual glue up, it went in all the way, no problem.

As an amateur, I'm sure I overthought this and probably just could have shimmed it. But the important thing is that the toilet is installed and flushing

Thanks again!

View attachment 68160

Perfect ! thats better than shim , sometimes I run my sawsall around it especially an offset ring. nice clean work you did